The more distinctive varieties of Highland English show the influence of Gaelic most clearly in pronunciation, but also in grammar. For example, voiceless stops /p/ /t/ /k/ are realised with preaspiration, that is as [hp], [ht] and [hk] or [xk], whereas voiced consonants tend to be de-voiced. Examples; that "whatever" becomes pronounced as "whateffer" and the English "j" as in "just" sound is often turned into a "tch" sound e.g. "chust". English /z/ may be realised as [s], giving "chisas" ("Jesus").[4] Some speakers insert a "sh" sound in English "rst" clusters, so that Eng. "first" gives "firsht". The lack of [w] in Gaelic may have led to its realisation in Highland English as [u], as in [suansi] ("Swansea").

Similarly, the svarabhakti ("helping vowel") that is used in some consonant combinations in Gaelic and Scots is sometimes used, so that "film" may be pronounced "fillum".[5]

Many older speakers employ a very distinctive affirmative or backchannel item taken from Scottish Gaelic which involves an ingress of breath[6] with clearly audible friction and whose function to indicate agreement with what a speaker has just said or is saying or to indicate continuing agreement or comprehension. This phenomenon has been termed by some "the Gaelic Gasp".[7] This linguistic feature is not found in the other Gaelic languages (Irish and Manx), but is present in some Scandinavian languages.[8] (Similarly, in France people often whisper the word "oui" while inhaling.)

The grammatical influence of Gaelic syntax is most apparent with verbal constructions, as Scottish Gaelic uses the verb to be with the active participle of the verb to indicate a continuous action as in English, but also uses this construction for iterative meanings; therefore "I go to Stornoway on Mondays" becomes "I am going to Stornoway on Mondays". Occasionally older speakers use -ing constructions where Standard English would use a simple verb form, example "I'm seeing you!" meaning "I can see you!". The past tense in Highland English may use the verb to be followed by "after" followed by the participle: "I am after buying a newspaper" to mean "I have [just] bought a newspaper", although this construction is more common in Irish English. Some speakers use the simple past in situations where standard English would require "have" plus verb constructions, for example "France? I was never there" rather than "I have never been there".

The diminutive -ag is sometimes added to words and names, and is a direct lift from Gaelic, e.g. Johnag, Jeanag. It is still used in Caithness as well. A great variety of distinctive female names are formed using the -ina suffix appended to male names, examples: Murdina ( < Murdo), Dolina, Calumina, Angusina, and Neilina.

Discourse markers taken directly from Gaelic are used habitually by some speakers in English, such as ending a narrative with "S(h)in a(g)ad-s' e" or "Sin agad e" (trans. "there you have it" = Std Eng. "So there you are/so that's it"), or ending a conversation with "Right, ma-thà" or "Okay ma-thà" /ma haː/ meaning "then".

Speakers of Highland English, particularly those from areas which remain strongly Gaelic or have a more recent Gaelic speaking history, are often mistaken as being Irish by some non-Highland Scots; presumably as a result of the shared Gaelic influence upon the English of both areas. Highland English and Hiberno-English share a similar accent which is quite different from that of the English spoken in Lowland areas of Scotland.

A list of words that appear in Highland English, although these are sometimes shared with Scottish English in general, as well as Lowland Scots, and to other areas where Highlanders have emigrated in large numbers.

^The Gaelic Gasp* and its North Atlantic Cousins, Eleanor Josette Thom, A study of Ingressive Pulmonic Speech in Scotland. A dissertation submitted in partial fulfilment of the requirements for the MA in Linguistics, University College London. September 2005